Improvement in regulators for electric lamps



E. THOMSON 82; E. J. HOUSTON. Regulator for Electric-Lamp.

Patented Oct. 14, 1879.

q) WITNESSES. A K INVENTORS m ZZ/QW ELIHU THOMSON AND EDTVIN J. HOUSTON,OF PHILADELPHIA, PA.

IMPROVEMENT IN REGULATORS FOR ELECTRIC LAMPS.

Specification forming part of Letters Patent No. 220,508, dated October14, 1879;

application filed June 11, 1879.

To all whom it may concern:

Be it known that we, ELIHU THOMSON and EDWIN J. HOUSTON, both of thecity and county of Philadelphia, Pennsylvania, have invented certainImprovements in Regulators for Electric Lamps, whereby we are enabled tooperate one or more lamps in a circuit, and at the same time to preventgreat and sudden variations in the arc-resistances, of which thefollowing is a specification.

This we accomplish by causing the distance between the carbon electrodesto remain nearly the samewhile the current is passing, while one of thefeatures of our invention is that the feeding of, and consequently thedistance between, the electrodes is practically independent of thestrength of the current used with the lamp, so that the adjustment ofsaid lamp need not be changed in accordance with a change in the currentstrength.

An extended series of investi gations conducted by us has developed thenovel fact that for arcs of equal len gth the electrical resistance ofsaid arcs is approximately in the inverse proportion of thecurrent-strength, and that, conse- 1 qnently, with a carbon arc, thecurrent which traverses a shunt around said are is a pproximatelyindependent of the current strength, varying with the length of the arebetween the electrodes. These facts we utilize in the construction andoperation of our present invent-ion.

The principle of our present invention may be briefly stated as follows,viz: One of the carbon electrodes is attached to the armature of anelectromagnet, and, on the passage of an electric current, said armatureis attracted to said electro-magnet, and then held in a fixed positionin respect thereto, thus efleetin g separation of the electrodes. Themotion of the other electrode is under the control of a separateelectro-magnet, whose coils are in a shuntcircuit around the are betweenthe electrodes. When the distance between the electrodes is I increasedby their consumption, the shunted 1 current operates an escapemen t,which allows I the slow approach of the electrode. Said approach ceaseswhen the distance between the I electrodes has reached the normal. Thiscessation of feeding occurs when the escapcment above referred to isthrown out of action from the weakening of the current in theshuntanagnet. These actions, as we have before stated, are independentof considerable variations in the current strength.

'We are aware that shunt-circuits have before been used in connectionwith electric regulators, but in our invention we employ theshunt-circuit in connection with a novel arrangement of parts designedto render the feeding of the carbon electrodes, as necessitated by theirconsumption, dependent on their distance apart, and nearly independentof general current strength and of a changed resistance of the are,produced by a change in the current strength.

To effect this end, we discard entirely, as a means of regulating thelamp, the general arc-current, or current traversing the are, male ingsaid regulation entirely dependent upon the magnetic power of a constantshunt-circuit around the are.

Some of the advantages gained by this arran gement are that the lengthof the arc may be set for each lamp and remain independent of variationsin the current strength or resistance of the are consequent thereon. oare also enabled to maintain the length of the are approximatelyconstant, and avoid, during operation, sudden movements of theelectrodes toward or from each other, thus avoiding the unsteadinesswhich results in many common forms of electric lamps due to theelectrodes being suddenly and violently thrust together when feeding ofthe electrodes is needed, consequent on increased length of arc.

Figure 1 is a side elevation, and Fig. 2 atop View, of a lamp embodyingthe principles of our invention. Y

Similar letters of reference are used to in dicate, similar parts in thefigures.

The carbon electrodes E Eare held by suitable elamps O O, and shown asconsisting of two pieces brought together by screws, and whose innersurfaces are shaped to conform to the outline of the electrodes. Thelower electrode-holderis attached to amova-ble arnia ture, N N, of anelectro-magnet, M M, and

lower electrode, E.

kept out of contact therewith, when the lamp is out of use, by thesupportingspring S, the strength and position of which is regulated bythe screw Q, which is made hollow to permit the passage through it ofthe electrode E, as shown.

Itods G G support the magnet M M and the accompanying parts, and serveas a means of attachment to the parts supporting the electrode E.

The upper electrode, E, is supported by the rod It, and suitably guided,so as to be ver tically above the electrode E. The rod R rests infrictional contact with the rollers P P ,the surfaces of contact ofwhich are shaped to conform to the section of the rod One of saidrollers P is supported in a fixed standard, while the other, P, isarranged so as to admit of adj ustment to and from the rod R by a bentlever, L, and a screw, T, or other suitable adjusting device. Thepressure which the rollers P P exert on the side of the rod It is madesuch that the rod cannot fall or descend without imparting rotary motionto the roller P, upon the axis of which is placed a toothed wheel IV,which in turn imparts motion to a second axis, bearing a second toothedwheel, W. A projection from a light iron armature,A,held by the spring Zagainst the wheel IV, serves to prevent its rotation, and consequentlyto prevent the fall or descent of the electrode E.

The electro-magnet K, whose position with respect to its armature A isadjustable, is placed in a branch or shunt circuit around the electrodesE E.

hen desired the wheel IV may be dispensed with, and the armature A actdirectly on the teeth of the wheel \V.

The circuit-connections are as follows, viz: The current entering at thebinding-post X passes to the rod R, to the electrode E, through the arcto E, thence through the coils of the electro-maguet M M to the rod G-and to the binding-post Y. The current entering the lamp is, however,branched through a shunt, D, of high resistance, of which the coils ofthe electro-magnet K form a part, and the extremities of which shunt arein electrical connection with the rod It, supporting the upperelectrode, E, and the armature supporting the The resistance of theshunt I) is made two or three hundred times that of the are which itcontrols, and thus but one two-hundredth or less of the work of thecurrent is lost in the shunt-circuit. I

The operation is as follows: The spring S maintains the armature N N inan elevated position, and consequently the electrodes E E in contact,when the lam pis notin use. 011 the passage of the current the armatureN N is drawn down closely to the magnet-cores M M, being prevented fromcoming into actual contact therewith by a thin layer of interposednon-magnetic material. During the passage of the current through thelamp the electrode E is thus held in a fixed position, and is not freeto oscillate, this result bein the proper regulation of the spring screwQ.

Assuming a separation of the electrodes E E to have taken place, theupper electrode, E, being prevented from falling by the armature Acatching in the teeth of the wheel \V, as before described, the positionof the electrodes remains constant until the length of the arc has beenincreased by the consumption of the electrodes, and the currenttraversing the shunt-circuit D likewise increased, at which moment theelectro-magnet K attracts its an mature A, so that it no longer catchesin the teeth of the wheel IV. At this moment the electrode E begins todescend slowly, giving rotation to the wheels W, a weight, 13, theamount of which can be varied, permitting the rapidity of descent to beregulated.

Several of the teeth of the wheel W escape the armature A until, by theapproach of the electrodes, the distance between them has becomenormal,the current traversing the shuntcircuit has become normal, thearmature A catching in the teeth of the wheel \V, as at first, arreststhe downward movement.

It is not essential that the shunt D have permanent attachment with themain circuit, as it will perform its ollice almost equally well ifbrought into periodical contact therewith, as every minute, any suitabledevice being employed to effect such periodical contact. In this case asaving of power in operating the shuntcircuit results.

It is evident to those versed in the art that by causing the movement ofthe upper electrode to give a corres ionding upward movement to thelower electrode, the relative rapidity of whose motion is less than thatof the upper electrode, the lamp will. regulate both electrodes, and theposition of the are between the electrodes will remain p 'acticallyconstant, the regulation of the lamp still bein effected by the samemethod as hereinbefore described.

We cl aim- 1. In an electric lamp, a rod, It, bearing the upperelectrode, in combination with rollers P P, resting in frictionalcontact with said rod, so arranged that during the fall otsaid electrodethe supportingrod It imparts rotary motion to the rollers I P, which inturn impart motion to the toothed wheel or its equivalent, substantiallyas described, and for the purpose specified.

2. In an electric lamp, the rod Pt, supporting the upper electrode,prevented from descendin by the frictional contact of the rollers P P,which rollers, acting in combination with the armature A, as described,are prevented from rotating when the magnetic attraction upon saidarmature is weakened, substantially in the manner described.

8. In an electric lamp, ii-ictioirrollers 1 P, resting in contact withthe red It, supporting the upper electrode, the pressure of whichcontact is adjustable, substantially in the manner described, so that bythe upward or downward g secured by S by the movement of said rod rotarymotion is imparted to said rollers P P, or their, equivalent, for thepurpose specified.

4. In an electric lamp, the combination of an armature, A, of ashunt-magnet, K, with a train of wheels, W W, in such a manner that whenthe power of the sh unt-magnet increases, the armature, acting as anescapement, allows rotation of said wheels, and when the power of theshunt-magnet decreases the armature acts to check such rotation, in themanner substantially as described.

5. In an electric lamp, the combination, with the electrode E, of therod It, friction-rollers P P, or their equivalents, wheel W, armature A,acting as an escapement to said wheel, and shunt-magnet K, all operatingtogether as a means of regulating and controlling the downward motion orfeeding of said electrode, in the manner substantially as described.

(3. In an electric lamp, the combination of the rod It, thefriction-rollers P P, wheel armature A, and shunt-magnet K, for thepurpose of controlling and regulating the position of the upperelectrode, E, in the manner described, with the armature N N, theelectromagnet M M, for the purpose of effecting the separation of theelectrodes and main taining the electrode E in a fixed position duringthe operation of the lamp.

ELIHU THOMSON. EDWIN J. HOUSTON.

Witnesses:

J. R. MASSEY, FRANK H. MAssEY.

